Interesting observations. In general, yes, people are thinking about long term plans, at Blackhawk and most of our trails. Keeping up with maintenance of existing trails is, as you note, often a challenge, and that often, though not always, takes precedence over major improvements. What gets ridden the most gets the most attention, which can lead to a downward spiral for some less popular trails. I've been heading up the good fight on several trails you mention for years, not always as successfully as I would like.
Some thoughts:
3,4. Deer Run is open to improvements. There's not alot of room in there, but if someone wanted to put time into improving it, either at the entrance/approach or further down, you would likely get support. I don't see it getting pro help in the near future, so it would be up to volunteers. Perhaps Trail Steward Pat Remington will chime in on that, or reach out to him directly: patrick.remington@madcitydirt.com
5. Upper gulley is a return for the jump line. People may still ride it down, but the the 'do not enter' sign at the top is meant to discourage that. Though perhaps that sign is gone? I only ride up, so might not notice if it disappeared.
6. Lower gulley is a bit of an orphan. Some people like it, so it still exists. May be up for work this fall? It doesn't do much for me, so I rarely ride it.
7,8,9. The hill 6 single track (Long's Short Trail and the unnamed section up higher) get ridden every time I am there (once a week, usually) and by anyone I can convince to ride with me, and they are entirely rideable going up, there is one turn on the upper section that may not be rideable going down, but it's more fun as a climb than a downhill anyway. This is excellent old-school technical riding and definitely part of keeping BH diverse and amazing. And they get more traffic than you think. Though the Small Switchbacks and Island (which you don't mention, did you find those?) are similar and get more traffic. And are slated for being supplanted this fall.
11. Yes, someday.
If you'd like to get involved in making anything you'd like to see happen happen, reach out. That's how it gets done.